@yukinoh1989 – Yes, if no one of our team has an available render, SheepIt will render other projects.
The short answer to how to Add a Project is: From the SheepIt website, go to the Projects Page and press the “+ Add your project” button. From there, just follow the instructions.
The long answer is to view a Youtube video: https://www.youtube.com/watch?v=D7ku2EcloGI. While the video may be a couple of years old, and the screens are different, the basics are there.